Thermally controlled roof ventilator damper



Nov. 17, 1959 R. B.-COE

THERMALLY CONTROLLED ROOF VENTILATOR DAMPER Filed May 12, 1958 FIG.

INVENTOR.

ROBERT a. COE

ll til all FIG. 2

ATTORNEYS THERMALLY CONTROLLED ROOF VENTILATOR DAMPER Robert B. Coe, La Crosse, Wis., assignor to The Irane Company, La Crosse, Wis., a corporation of Wisconsin Application May 12, 1958, Serial No. 734,459

5 Claims. (Cl. 98-119) in case of fire. This was done to prevent the creation of a draft which would fan the flame and possibly spread the flame to remote areas thereby causing considerable damage outside the immediate area of the fire. This practice has been followed for a number of years throughout the country by fire prevention and fire fighting associations. A couple of years ago a disastrous fire leveled a so-called fire proof building of one story industrial type construction. An investigation was made at the scene of this fire and the conclusion was formed that the above mentioned concept is generally sound but that exceptions should be made. The major exception set forth being that automatic control means should be incorporated in all ventilating equipment of large one story industrial type buildings which use or produce large quantities of highly inflammable material of high smoke producing characteristics so that the dampers of said ventilating equipment will automatically open to vent the building in case of fire. Otherwise, the smoke producedwill so hamper the fire fighting teams that they will be unable to effectively combat the fire. Normally, the above automatic control means should be used in conjunction with an adequate sprinkler system in order to allow the smoke to escape but yet keep the fire under control.

In light of the above problem, it is an object of this invention to provide a means to automatically open the gravity operated dampers of a roof ventilator normally used in large single story industrial buildings.

It is a further object of the invention to provide torsion springs on the damper blades of a roof ventilator with the ends of the springs secured together by a fusible link which, upon an excessive rise in temperature due to fire, will automatically open said dampers to vent the smoke from inside the enclosure.

Other objects and advantages of the invention will be clearly apparent as the specification proceeds to describe the invention with reference to the accompanying drawings in which:

Fig. 1 is a front elevation view of a roof ventilator with the casing broken away showing the apparatus of the invention partially in section.

Fig. 2 is a partial section view on line 2-2 of Fig. 1 with the fan and fan hub removed.

Fig. 3 is a top plan view of the torsion spring with the ends of the spring secured in the inoperative position by a fusible link.

Referring now to Fig. 1, reference number 10 designates a typical vertical exhaust roof ventilator normally supported over an opening in a roof of an industrial building by base support 12. Basically, roof ventilator 10 consists of a fan 13 directly connected to a driving motor United States Patent ice vby brackets 25 attached by welding or any other suitable means to orifice extension 20.

When fan 13 is operating, air is drawn from the enclosure through air inlet orifice 18 and forced through orifice extension 20 against butterfly damper blades 26 and 28 forcing them upward until stopped by damper stops 30. Damper stops 30 are mounted in any desired manner on damper stop support member 32 which in turn is welded or otherwise attached to channel bracket 34. Channel bracket 34 extends transversely across windguard 22 and is secured to the sides thereof.

When the fan 13 ceases to operate, the weight of damper blades 26 and 28 causes them to close by gravity. An extruded plastic seal 36 is placed on the edge of orifice extension 20 to eliminate air leakage around the damper blades 26 and 28 when the roof ventilator is not in use.

Damper blades 26 and 28 are rotatably supported on shafts 38 and 40 held at the ends by shaft support 42.

.Shaft support 42 is welded or attached in any manner desired to orifice extension 20. Note that damper blades 26 and 28 are inclined downwardly from the horizontal position when inoperative to provide drainage and rain protection.

In Fig. 1, my invention is shown in the inoperative position on damper blade 26 and in the operative position on damper blade 28. In accordance with my invention, a torsion spring 44 is mounted on damper blades 26 and 28 by securing one end of the spring to the damper blades by nuts 46 and bolts 48 or any other suitable means.

The torsion spring 44, as shown on damper blade 26, is held in the inoperative position by a fusible link 52 which connects ends 50 and 54 of torsion spring 44. The fusible link 52 is located in a notch 56 on spring end 50 in order to avoid sliding of the link along the spring ends so that the possibility of inadvertent opening of the damper blades is avoided.

As is readily seen, the torsion spring 44 when inoperative will rotate with the damper blades as the fan cuts on and off.

If a fire should start within the enclosure and the temperature should rise to the melting point of the fusible line 52, normally 160 F., the fusible link will melt, thereby releasing spring ends 50 and 54. As shown on damper blade 28, spring end 54 will rotate until it strikes plate 58 which is secured to channel section 60 extending between and secured to the orifice extension 20 by any suitable means. When the spring end 54 strikes the plate 58, the other end 50 of the torsion spring 44 will rotate outwardly due to the bias of the spring and, since it is attached to the damper, will rotate the damper blade to the open position as shown by damper blade 28 thereby venting the enclosure. The damper blades will be held in the open position until such time the spring bias is counteracted by manual resetting of the spring.

From the foregoing description, it is readily understood that I have provided a simple and reliable damper opener which will automatically operate in case of fire to open the damper blades of a roof ventilator in order to vent the fumes from within the enclosure over which the above ventilator is mounted.

Although I have described in detail the preferred embodiments of my invention, I contemplate that many changes may be made without departing from the scope or spirit of my invention, and I desire to be limited only by the claims.

I claim:

1. In a roof ventilator, a damper blade hinged to said ventilator, a torsion spring having a first end and a second end projecting outwardly therefrom, said first end being mounted on said damper blade, heat destructible means connecting said first end and said second end, and means secured to and supported by said ventilator below said second end to support said second end when said heat destructible means is destroyed by heat to cause said first end to open said damper blade when said heat destructible means is destroyed by heat.

2. In a roof ventilator, a pair of damper blades hinged to said ventilator, a pair of torsion springs each having a first end and a second end projecting outwardly therefrom, said first ends being mounted on said damper blades, heat destructible means connecting said first ends and said second ends respectively, and means secured to and supported by said ventilator and located below said second ends to support said second ends when said heat destructible means are destroyed by heat to cause said first ends to open said damper blades when said heat destructible means are destroyed by heat.

3. In a roof ventilator, a pair of damper blades hinged to said ventilator, a pair of torsion springs, each with a first end and a second end, said first ends being mounted on said damper blades, fusible links connecting said first ends to said second ends, a plate secured to said ventila tor below said second ends whereby said second ends will strike said plate when said fusible links are destroyed by 4 heat thereby causing said first ends to open said damper blades.

4. In a roof ventilator, a pair of damper blades hinged to said ventilator, a pair of torsion springs, each having a first end and a second end, said first ends being mounted on said damper blades, fusible links connecting said first ends to said second ends, a bar member disposed parallel to the hinge lines of said blades and attached to said ventilator, a plate member disposed normal and attached to said bar member below said damper blades whereby said second ends will strike said plate when said fusible links are destroyed by heat thereby causing said first ends to open said damper blades.

5. In a roof ventilator, a damper blade hinged to said ventilator, a torsion spring with a first end and a second end, said first end being mounted on said damper blade, a fusible link connecting said first end to said second end, a plate secured to said ventilator below said second end whereby said second end will strike said plate when said fusible link is destroyed by heat thereby causing said first end to open said damper blade.

References Cited in the file of this patent UNITED STATES PATENTS 

